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Diffstat (limited to 'dom/media/webaudio/blink/HRTFKernel.h')
-rw-r--r-- | dom/media/webaudio/blink/HRTFKernel.h | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/dom/media/webaudio/blink/HRTFKernel.h b/dom/media/webaudio/blink/HRTFKernel.h new file mode 100644 index 0000000000..34479f6301 --- /dev/null +++ b/dom/media/webaudio/blink/HRTFKernel.h @@ -0,0 +1,129 @@ +/* + * Copyright (C) 2010 Google Inc. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of + * its contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef HRTFKernel_h +#define HRTFKernel_h + +#include "nsAutoRef.h" +#include "nsTArray.h" +#include "mozilla/FFTBlock.h" +#include "mozilla/MemoryReporting.h" +#include "mozilla/UniquePtr.h" + +namespace WebCore { + +using mozilla::FFTBlock; +using mozilla::UniquePtr; + +// HRTF stands for Head-Related Transfer Function. +// HRTFKernel is a frequency-domain representation of an impulse-response used +// as part of the spatialized panning system. For a given azimuth / elevation +// angle there will be one HRTFKernel for the left ear transfer function, and +// one for the right ear. The leading delay (average group delay) for each +// impulse response is extracted: +// m_fftFrame is the frequency-domain representation of the impulse +// response with the delay removed +// m_frameDelay is the leading delay of the original impulse response. +class HRTFKernel { + public: + // Note: this is destructive on the passed in |impulseResponse|. + // The |length| of |impulseResponse| must be a power of two. + // The size of the DFT will be |2 * length|. + static nsReturnRef<HRTFKernel> create(float* impulseResponse, size_t length, + float sampleRate); + + static nsReturnRef<HRTFKernel> create(UniquePtr<FFTBlock> fftFrame, + float frameDelay, float sampleRate); + + // Given two HRTFKernels, and an interpolation factor x: 0 -> 1, returns an + // interpolated HRTFKernel. + static nsReturnRef<HRTFKernel> createInterpolatedKernel(HRTFKernel* kernel1, + HRTFKernel* kernel2, + float x); + + FFTBlock* fftFrame() { return m_fftFrame.get(); } + + size_t fftSize() const { return m_fftFrame->FFTSize(); } + float frameDelay() const { return m_frameDelay; } + + float sampleRate() const { return m_sampleRate; } + double nyquist() const { return 0.5 * sampleRate(); } + + size_t sizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const { + size_t amount = aMallocSizeOf(this); + amount += m_fftFrame->SizeOfIncludingThis(aMallocSizeOf); + return amount; + } + + private: + HRTFKernel(const HRTFKernel& other) = delete; + void operator=(const HRTFKernel& other) = delete; + + // Note: this is destructive on the passed in |impulseResponse|. + HRTFKernel(float* impulseResponse, size_t fftSize, float sampleRate); + + HRTFKernel(UniquePtr<FFTBlock> fftFrame, float frameDelay, float sampleRate) + : m_fftFrame(std::move(fftFrame)), + m_frameDelay(frameDelay), + m_sampleRate(sampleRate) {} + + UniquePtr<FFTBlock> m_fftFrame; + float m_frameDelay; + float m_sampleRate; +}; + +typedef nsTArray<nsAutoRef<HRTFKernel> > HRTFKernelList; + +} // namespace WebCore + +template <> +class nsAutoRefTraits<WebCore::HRTFKernel> + : public nsPointerRefTraits<WebCore::HRTFKernel> { + public: + static void Release(WebCore::HRTFKernel* ptr) { delete (ptr); } +}; + +namespace WebCore { + +inline nsReturnRef<HRTFKernel> HRTFKernel::create(float* impulseResponse, + size_t length, + float sampleRate) { + return nsReturnRef<HRTFKernel>( + new HRTFKernel(impulseResponse, length, sampleRate)); +} + +inline nsReturnRef<HRTFKernel> HRTFKernel::create(UniquePtr<FFTBlock> fftFrame, + float frameDelay, + float sampleRate) { + return nsReturnRef<HRTFKernel>( + new HRTFKernel(std::move(fftFrame), frameDelay, sampleRate)); +} + +} // namespace WebCore + +#endif // HRTFKernel_h |